Design and analysis of absorbing cavity in full absorbing HEL rotational calorimeter

The method full absorbing is the most commonly technique to measure total energy of high energy laser(HEL), which is one of important technical indexes for parameters test of HEL. In order to improve the ability of laser damage resistance, in comprehensive consideration of work mode and temperature field distribution of energy absorbing graphite, a novel HEL rotational calorimeter was designed. The calorimeter especially applicable to laser long-time irradiation has a series of advantages, such as low measurement uncertainty, uncomplicated configuration and environmental adaptability. Numerical simulation results through method of ray tracing show that laser energy loss is less than 0.3 percent. The software based on finite element method was used to analyze temperature field distribution and maximum of absorb material, rotate speed-dependent temperature, temperature curve at the different positions of temperature sensor. Simulation results indicate that the calorimeter can be applied to several ten million joule(MJ) energy of HEL successfully, and provides a novel technique way for measurement of higher laser energy.